Toronto public health officials are monitoring 170 people connected to Seven Oaks Home for the Aged in Scarborough, a bedroom community just east of Toronto, including families and children who attend a day-care center in the building.
While Seven Oaks is not under quarantine, visitors have not been allowed in for several days.
The Monday night deaths of two women, aged 95 and 79, brings the death count to six.
Anxiety over the outbreak has been exacerbated by renewed fears of SARS - severe acute respiratory syndrome - which claimed 44 lives in Toronto from two outbreaks in early 2003. More than 8,000 people worldwide contracted the illness and some 774 people died.
One of those who survived the SARS outbreak in Toronto was Dr. Allison McGeer, an infectious disease specialist at Mount Sinai Hospital. On Monday she ruled out SARS, avian flu, Legionnaires and influenza A and B, while emphasizing there was no cause for alarm.
Health officials have yet to determine whether the illness is a virus, bacteria, or a combination, but state the outbreak is a "garden variety" respiratory illness that mostly targets the elderly, who are typically more vulnerable to infection.
Dr. David McKeown, Toronto's medical officer, says there have been 39 respiratory outbreaks at long-term care facilities in Ontario since Sept. 1.
